Since the 1970s, the prevalence of obesity in children ages 2 to 5 has approximately tripled. Millions of American children in that age group spend substantial time each week in child care, and factors related to obesity are not optimal in those settings. Therefore, it is important to understand how policies and practices in child care settings influence factors that may be related to obesity. In South Carolina (SC), a state with high rates of obesity among all population groups, the Department of Social Services plans to implement new healthy eating and physical activity regulatory standards that govern family child care homes that participate in the state's ABC Child Care program. The program includes 368 family child care homes serving approximately 3,000 children from low-income families; 65% of children are from minority racial or ethnic backgrounds. The standards target meals and snacks served to children and the amount and level of physical activity provided to children in care. The new regulatory standards will be announced to family child care homes shortly. This proposed study will evaluate the implementation and effects of South Carolina's new regulatory standards, which are designed to improve the quality of their diets and increase children's physical activity levels while they are in care. Data will be collected on a sample of 360 children attending 120 family child care homes in South Carolina before and at two time points after the standards take effect. The ABC Child Care program will announce the new standards shortly, and they will become mandatory in October of 2017. The launch of new standards in South Carolina provides a narrow time window and a unique opportunity to study the effects of a key policy change?markedly enhanced state regulatory standards for physical activity and quality of food* served?on physical activity levels and diet of children attending family child care homes. Results from this study will provide new information on state policy change and its influence on healthy eating and physical activity levels of children in family child care homes. Policy-based obesity prevention efforts have the potential to impact and improve the health of large numbers of children attending family-based child care in South Carolina and across the country.